Husqvarna Automower 105 Compatible Battery 18V 2500mAh

Husqvarna Automower 105 (2016–2019) — 18V Li-ion Replacement Battery

This 18V 2500mAh (45Wh) lithium-ion battery fits the Husqvarna Automower 105 from the 2016 through 2019 model years, along with 15 additional compatible variants. It powers the blade motor, drive wheels, and onboard navigation that keep the mower running its programmed pattern without input. Swap it in when the original pack no longer holds enough charge to complete a full mowing cycle.

• Automower 105 (2016–2019) compatibility: These model years share the same 18V battery bay, connector pinout, and BMS handshake protocol. The pack slots in and communicates state-of-charge to the mower's onboard controller the same way the factory unit does.
• Bench tested on actual hardware: We cycled this pack through repeated charge and discharge sequences, monitoring BMS response to inrush current spikes that mirror blade motor start-up load. The protection circuit held voltage within the expected window throughout.
• Spring recommission tip: Before the first mow of the season, bring the battery indoors overnight if the temperature is below 10°C. Cold Li-ion cells carry higher internal resistance, and the blade motor's inrush current can trip the BMS on a pack that hasn't warmed up yet.

Charger showing fault after the mower sat in the garage all winter

Li-ion cells self-discharge slowly during storage. Over a full winter, a pack left in the mower or on the shelf can drop below the minimum acceptance voltage the charger checks before it will begin a charge cycle. When the voltage reads too low, the charger raises a fault rather than risk charging a damaged cell. The fix is to check the pack's resting voltage with a multimeter — if it reads above 12V, most chargers will recover it with a slow pre-charge cycle. If it reads below 10V, the cells have likely gone into deep discharge and the pack should be replaced.

Mower cuts out mid-row then restarts on its own

This is thermal protection triggering, not a faulty battery. When the blade motor works hard through thick or wet grass, current draw spikes and the pack's BMS trips to prevent cell damage from excess heat. The mower stops, the BMS resets after the pack cools, and the unit restarts. Let it sit for at least five minutes before manually restarting. If the cutouts become frequent in normal conditions, check that the blade is sharp — a blunt blade forces the motor to draw more current on every rotation, and that sustained load is what pushes the BMS over its threshold.